CheerpJ Applet Runner icon

CheerpJ Applet Runner

by Leaning Technologies Ltd

v2026.3 Updated Mar 11, 2026 121MiB
CWS
100K
Users
★ 4.53
279 reviews
#1104
of 207.6K
workflow
#371 of 31.9K
Highly rated Recently updated

Description

CheerpJ Applet Runner - Run Java applets without installing Java With the CheerpJ Applet Runner extension, you can run legacy Java Applets on modern browsers without a Java plugin or a Java installation. Using the CheerpJ Applet Runner is simple. Just install and pin the extension. Next, visit your Applet-based website, click the extension icon in the upper-right corner of your browser, and then press the 'Enable' button in the popup. Once enabled, the extension is activated for the current domain, and Applets will start automatically if they are present. This extension works by 'converting' the Java Applet to WebAssembly and JavaScript on the fly. It is private and secure, runs fully client-side (i.e. it does not contact any server), and does not collect any data or analytics at all. All your data, as well as your application are kept within the boundaries of your browser. This extension, developed by Leaning Technologies, is based on CheerpJ, a JVM/JRE replacement for modern browsers. More information on CheerpJ are available at https://www.cheerpj.com. This software is free to use for non-business purposes on public-network Applets. For any other use, such as internal network applets, or if you are a company or public-sector organisation and would like to license CheerpJ, please get in touch with sales@leaningtech.com.
CheerpJ Applet Runner screenshot 1CheerpJ Applet Runner screenshot 2CheerpJ Applet Runner screenshot 3CheerpJ Applet Runner screenshot 4CheerpJ Applet Runner screenshot 5

Reviews (19 cached)

★☆☆☆☆2024-08-12
Abhinav Hingaa

Not working on actual Applet based website. Try this on https://ireps.gov.in/appletTest.html. Not working on this website. However this website (https://ireps.gov.in/appletTest.html) is working on Microsoft Edge in IE mode.

★☆☆☆☆2024-06-14
JD Saidi

Doesnt work, the page doesnt load the applet

★☆☆☆☆2023-11-17
Michael Wynn

Does not work when a second window is opened from the original applet, have to kill the browser tab to progress.

★☆☆☆☆2023-04-08
Fretta

Useless

★☆☆☆☆2022-03-24
Cesar Augusto Pareja Gonzalez

Does not work

★☆☆☆☆2022-03-19
Al Fargnoli

It has stopped working for me.

★☆☆☆☆2022-02-28
Mohsin

after 77mb of download it informs you that file urls are not supported!!!

★☆☆☆☆2021-11-02
Evgeniy Kh

do not work

★☆☆☆☆2017-12-24
Hassan Raza

I'm a student and new to to java. I made a simple famous "Hello World" JApplet and try to run on chrome using "CheerpJ Applet Runner Beta" But it didn't wort at all on my side. Hopefully someone help me. If it work on my side I'll give 5 star. Thanks

★☆☆☆☆2017-11-25
Gill M

DOESN'T WORK at ALL with Java Applets.....tried on the very popular site www.netdania.com/Charts vs FinanceChart......

★☆☆☆☆2017-08-26
ad zwemer

it does'nt even work

★★☆☆☆2024-07-26
Jake Rumberger

noble idea but wont run on my netgear switch...

★★☆☆☆2022-04-01
Yuna

Cant say I can give a review on the extension fully when I have yet to see it working on any site I try to use it on. with changes google have made to stop supporting java this seemed like an ideal solution to get me back to what I was doing. as of now the sites that don't work continue to not work. hopefully this is not the case for others. 2 stars just because its useful to some people so it warrants a small token.

★★☆☆☆2018-09-17
Alexandre Muller

It doesn't work

★★☆☆☆2018-01-22
Jack The Dragon

tried it on old school runescape doesn't work sadly would of gave 5 stars though

★★★☆☆2022-08-31
KentuckyFryedStalin

its pretty amazing, dont get me wrong. i have noticed some issues when an applet makes use of the older sun audio libraries. stuttering and the such. other than that, it got a game i haven't seen in ten years up and running again in the blink of an eye

★★★☆☆2021-09-02
Rei Tsukino

The stop applet feature needs to return. Constant on is causing issues. I don't mind it auto-starting but having no way to turn it off short of removal is an issue for some sites now.

★★★☆☆2019-06-07
David

Only works occasionally. For example, I was unable to launch Cisco AnyConnect via the web-browser portal.

★★★☆☆2019-03-09
Steve Baker

Tried the Rubik's cube demo and it keeps going to download the applet runner. Even after adding that extension it keeps returning to that page. Updated Chrome. Result the same. Cannot bring up the Rubiks cube demo???

Permissions (5)

Permissions

activeTab Can access the current tab when you click the extension alarms Can schedule periodic background tasks declarativeNetRequestWithHostAccess scripting Can inject scripts into web pages storage Can store data locally in your browser

Details

Version 2026.3
Updated Mar 11, 2026
Size 121MiB
First Seen Apr 1, 2026